Webster’s Revised Unabridged Dictionary · 1913
Sprue
Sprue (sprṳ), n. [Etymol. uncertain.] 1. (Founding) (a) Strictly, the hole through which melted metal is poured into the gate, and thence into the mold. (b) The waste piece of metal cast in this hole; hence, dross.
2. (Med.) Same as Sprew.